This study tested the hypothesis that running and in-line skating training elicit similar improvements in cardiorespiratory fitness. Changes in maximal oxygen consumption (VO2max) and maximal treadmill endurance time were compared in runners (N = 16), in-line skaters (N = 19), and controls who did no systematic training (N = 7). Training volumes were similar for runners and skaters (3 d.wk-1, 10-40 min/session, 80-90% of exercise specific maximal heart rate) and included both continuous and interval workouts. Pre- and post-training VO2max and maximal treadmill time were measured in all subjects using a running protocol and in skaters using an in-line skating protocol. The groups did not differ in pre-training running VO2max or maximal treadmill time. After 9 wk, significant increases in running VO2max and maximal treadmill time were observed in runners (mean +/- SE, 9.3 +/- 1.3%, 14.9 +/- 2.5%) and skaters (6.6 +/- 1.0%, 9.1 +/- 3.4%), but not controls. Skaters also significantly increased their skating VO2max and maximal treadmill time (8.6 +/- 1.8%, 7.9 +/- 2.9%). The magnitude of these increases was not different between the two training groups. In conclusion, in moderately active college-aged students, similar improvements in VO2max are achieved with running and in-line skating programs that are equivalent in training volume and intensity.